1. Technical Field
The present invention relates to a location calculating method and a location calculating device.
2. Related Art
As a positioning system using a positioning signal, a GPS (Global Positioning System) is widely known and is used for a location calculating device that is built in a cellular phone or a navigation device, or the like. In the GPS, a location calculating process is performed in which the coordinates of the location and the clock error of the location calculating device are acquired based on information including the locations of a plurality of GPS satellites, a pseudo distance from each GPS satellite to the location calculating device, and the like.
The location calculating device is also used by being built in various electronic apparatuses other than the electronic apparatuses such as the cellular phone and the car navigation device. For example, a technology is contrived in which photographed image data and positional information data are recorded in association with each other, for example, in a digital camera in which the location calculating device is built (for example, JP-A-7-307913).
In order to perform location calculation using the GPS, satellite orbit data of GPS satellites is necessary. However, when positioning is started in the state in which the satellite orbit data is not stored, that is, in a so-called cold start state or the like, a predetermined time interval is necessary for acquiring the satellite orbit data from the GPS satellites. On the other hand, for example, in a case where the above-described digital camera is used, the photographing process is completed in a short time. Accordingly, there is a problem in terms of time for completing the location calculating process at photographing time. When the process is similarly considered for other electronic apparatuses, there is a problem in terms of time for completing the location calculating process at given desired time.